+++ /dev/null
-/*******************************************************************************
- * Copyright (c) 2000, 2001, 2002 International Business Machines Corp. and others.
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the Common Public License v0.5
- * which accompanies this distribution, and is available at
- * http://www.eclipse.org/legal/cpl-v05.html
- *
- * Contributors:
- * IBM Corporation - initial API and implementation
- ******************************************************************************/
-package net.sourceforge.phpdt.internal.compiler.codegen;
-
-import net.sourceforge.phpdt.internal.compiler.util.CharOperation;
-
-public class CharArrayCache {
- // to avoid using Enumerations, walk the individual tables skipping nulls
- public char[] keyTable[];
- public int valueTable[];
- int elementSize; // number of elements in the table
- int threshold;
-/**
- * Constructs a new, empty hashtable. A default capacity is used.
- * Note that the hashtable will automatically grow when it gets full.
- */
-public CharArrayCache() {
- this(13);
-}
-/**
- * Constructs a new, empty hashtable with the specified initial
- * capacity.
- * @param initialCapacity int
- * the initial number of buckets
- */
-public CharArrayCache(int initialCapacity) {
- this.elementSize = 0;
- this.threshold = (int) (initialCapacity * 0.66f);
- this.keyTable = new char[initialCapacity][];
- this.valueTable = new int[initialCapacity];
-}
-/**
- * Clears the hash table so that it has no more elements in it.
- */
-public void clear() {
- for (int i = keyTable.length; --i >= 0;) {
- keyTable[i] = null;
- valueTable[i] = 0;
- }
- elementSize = 0;
-}
-/** Returns true if the collection contains an element for the key.
- *
- * @param char[] key the key that we are looking for
- * @return boolean
- */
-public boolean containsKey(char[] key) {
- int index = hashCodeChar(key);
- while (keyTable[index] != null) {
- if (CharOperation.equals(keyTable[index], key))
- return true;
- index = (index + 1) % keyTable.length;
- }
- return false;
-}
-/** Gets the object associated with the specified key in the
- * hashtable.
- * @param key <CODE>char[]</CODE> the specified key
- * @return int the element for the key or -1 if the key is not
- * defined in the hash table.
- */
-public int get(char[] key) {
- int index = hashCodeChar(key);
- while (keyTable[index] != null) {
- if (CharOperation.equals(keyTable[index], key))
- return valueTable[index];
- index = (index + 1) % keyTable.length;
- }
- return -1;
-}
-private int hashCodeChar(char[] val) {
- int length = val.length;
- int hash = 0;
- int n = 2; // number of characters skipped
- for (int i = 0; i < length; i += n) {
- hash += val[i];
- }
- return (hash & 0x7FFFFFFF) % keyTable.length;
-}
-/**
- * Puts the specified element into the hashtable, using the specified
- * key. The element may be retrieved by doing a get() with the same key.
- * The key and the element cannot be null.
- *
- * @param key <CODE>Object</CODE> the specified key in the hashtable
- * @param value <CODE>int</CODE> the specified element
- * @return int the old value of the key, or -1 if it did not have one.
- */
-public int put(char[] key, int value) {
- int index = hashCodeChar(key);
- while (keyTable[index] != null) {
- if (CharOperation.equals(keyTable[index], key))
- return valueTable[index] = value;
- index = (index + 1) % keyTable.length;
- }
- keyTable[index] = key;
- valueTable[index] = value;
-
- // assumes the threshold is never equal to the size of the table
- if (++elementSize > threshold)
- rehash();
- return value;
-}
-/**
- * Rehashes the content of the table into a bigger table.
- * This method is called automatically when the hashtable's
- * size exceeds the threshold.
- */
-private void rehash() {
- CharArrayCache newHashtable = new CharArrayCache(keyTable.length * 2);
- for (int i = keyTable.length; --i >= 0;)
- if (keyTable[i] != null)
- newHashtable.put(keyTable[i], valueTable[i]);
-
- this.keyTable = newHashtable.keyTable;
- this.valueTable = newHashtable.valueTable;
- this.threshold = newHashtable.threshold;
-}
-/** Remove the object associated with the specified key in the
- * hashtable.
- * @param key <CODE>char[]</CODE> the specified key
- */
-public void remove(char[] key) {
- int index = hashCodeChar(key);
- while (keyTable[index] != null) {
- if (CharOperation.equals(keyTable[index], key)) {
- valueTable[index] = 0;
- keyTable[index] = null;
- return;
- }
- index = (index + 1) % keyTable.length;
- }
-}
-/**
- * Returns the key corresponding to the value. Returns null if the
- * receiver doesn't contain the value.
- * @param value int the value that we are looking for
- * @return Object
- */
-public char[] returnKeyFor(int value) {
- for (int i = keyTable.length; i-- > 0;) {
- if (valueTable[i] == value) {
- return keyTable[i];
- }
- }
- return null;
-}
-/**
- * Returns the number of elements contained in the hashtable.
- *
- * @return <CODE>int</CODE> The size of the table
- */
-public int size() {
- return elementSize;
-}
-/**
- * Converts to a rather lengthy String.
- *
- * return String the ascii representation of the receiver
- */
-public String toString() {
- int max = size();
- StringBuffer buf = new StringBuffer();
- buf.append("{"); //$NON-NLS-1$
- for (int i = 0; i < max; ++i) {
- if (keyTable[i] != null) {
- buf.append(keyTable[i]).append("->").append(valueTable[i]); //$NON-NLS-1$
- }
- if (i < max) {
- buf.append(", "); //$NON-NLS-1$
- }
- }
- buf.append("}"); //$NON-NLS-1$
- return buf.toString();
-}
-}